Radhika, very thoughtful analyze,
Dev, is influenced & misguided by everybody about Barkha's good deeds & sacrificial status, by dada to daima to Padma & even his own wife Radhika. So now Radhika suddenly going totally against what she used to believe about her best friend was unbelievable to him. And so now there is an iron certain of Barkha's sacrifices built in front of him which has to be broken.
Rohan & Virat influenced by their mothers, & misguided by them while they were growing up. Their hidden good qulities had become dormant by superficial necessities, & those hidden good qualities has to be realized by themselves to fight the evil within themselves.
And you are right about daima , she was never selfish, her loyalties always lied with dada as "namak halal naukar' , never asked or raised a voice against his decision, & dada had more faith & relied on her with his secret than his own family. And as the time was passing by, she started to see & suspect that something is not right but could not pinpoint what, then she started to miss Radhika & her good qualities & she could see Dev's anguished & trauma over Radhika. She was missing that spirtuality & 'bhakti' which Radhika had brought with her in the house. And so after Dev she was the most happy to see Radhika back in home.
So Kanha is slowly going to blow away the dark clouds & bring in the sunshine for PH family to see clearly. I myself want all family together bec Dev & Radhika loves their family & as Kanha-Radhika said that there has to be repentance.